After the raging success of the likes of Eden Lake and Heartless, “Hoodie Horror” continues to make its mark on British cinema with Johannes Roberts’ F.

In its realisation of every teacher’s nightmare, F tells the story of experienced educator Robert Anderson (Schofield), who suffers a debilitating breakdown after being attacked in the classroom by one of his teenage students. When the school board refuses to back him legally for fear of any public or professional repercussions on the institution, we fast forward to find Anderson a broken man, estranged from his wife and daughter (whom he also teaches) and attempting to find solace at the bottom of a bottle.

Struggling to keep a thread of his relationships alive and maintain order in the classroom amidst snipes from those in charge who wouldn’t back him up previously, Anderson’s frustrations come to a head when he slaps his anger-venting daughter while holding her in detention. As she takes off to report his actions and phone her mother, both Anderson and the rest of the staff are unaware that the evening is about to take a deadly turn: A group of faceless, hooded youths have invaded the school with the intention of indiscriminately murdering everyone inside.

David Schofield is in fine form as the damaged Robert Anderson, delivering a touchingly sympathetic portrait of a man betrayed by not only the powers that be, but himself as well. All resolve lost, he simply inhabits his world as an empty, booze-reeking shell. Stripped of power in the classroom, he can do nothing but robotically present his teachings while children run amok around him. Slightly hyperbolic, sure, but not a million miles off the UK’s current classroom situations where students, backed up by needlessly meddling bureaucrats, gain the upper hand on those supposedly in authority. Even when he snaps, Schofield expertly delivers the immediate remorse and frustration of his character alongside the determination to ensure his daughter is safe. The subtlety of his performance may occasionally give rise to one or two unintentional chuckles, but for the most part he delivers a pitch-perfect representation of a man on the edge of the abyss forced to pull himself together to survive.

The hooded killers in F are also a highlight. With absolutely no dialogue given to them, they are essentially silent stalkers – and agile ones at that. Running up walls, parkour-style, crawling along lockers and bookshelves, and dropping down noiselessly behind victims are their forte; and it’s effectively chilling. Director Roberts keeps his villains’ faces hidden throughout the entire film – the inside of their hoods remaining a black pit – which gives them an almost otherworldly appearance. The hoodie performers also deserve a ton of credit for pulling off some seriously threatening body language which translates exceptionally well on screen when they’re squaring up to would-be victims.

While F certainly keeps up the tension admirably, it is much too anaemic in the violence department to be truly effective. Almost every single kill takes place either off-screen or with a hooded assailant swinging an object at the camera. In fact, only two after-the-fact discoveries truly display any grisly goods (although the prosthetics work is exceptional). A bit more punch or wanton brutality from the killers would have made the film much more fulfilling.

Another major cause of the rather empty feeling F leaves is the ending. While it does show an admirable amount of testicular fortitude in having its protagonist forced to make a gut-wrenching decision after having been put through the wringer, we are offered absolutely no insight into the motivations or possible identities of the killers nor the expected redemption through violence that almost comes as a given in this type of movie for the central character. It does happen but is delivered so feebly as to be rendered ineffectual. The closing moments allow this lack of substance to ring a final hollow tone as the closing extended shot lacks the poignancy or thoughtfulness it appears to think it has.

All in all, F is a pretty well crafted little shocker with stand-out performances but is far too ambiguous and lacking in violence for its own good. The villains are excellent, the lead is excellent, and the direction and score hit where they need to; but by the end you’ll likely be feeling too unsatisfied and unfilled to be truly appreciative. By no means a complete failure, F is a missed opportunity nonetheless.